Protective effect of Enterococcus faecalis DAPTO 512 on the intestinal tract and gut mucosa: milk allergy application.

The allergenicity of ß-lactoglobulin (ß-Lg) was studied by using Ussing chamber in a murine model of ß-Lg allergy supplemented with hydrolysates obtained after fermentation of milk for 48 h at 37 (°)C with Enterococcus faecalis DAPTO 512, isolated from cow milk and identified by 16S rDNA sequence analysis. Balb/c mice were sensitised intraperitoneally with ß-Lg. Three groups of mice were formed: group 1, composed of naive mice used as control received only NaCl; group 2, positive control composed of mice sensitised intraperitoneally with ß-Lg; group 3, formed by mice which were given hydrolysates of 48 h then sensitised with ß-Lg. After 48 h of fermentation ß-casein and ß-Lg were degraded by E. faecalis DAPTO 512. ß-Lg immunisation was associated with strong IgG and IgE production in case of positive controls and a significant increase in short current circuit (Isc) and high conductance (G) responses were observed. The control and the hydrolysate groups showed a significant decrease in the production of IgG and IgE anti ß-Lg compared to the positive control. The allergenic potential of ß-Lg was markedly reduced in the group that received hydrolysates (Isc and G remained unchanged after intestine challenge with ß-Lg). The histological scrutiny showed villi atrophy, lymphocyte hyperplasia and a significant chorion detachment in the positive control group. In the group administered with hydrolysates of fermented milk, inflammatory signs were lower, the villi were long and thin and lymphocytes were less dense. The results showed that feeding of milk fermented with E. faecalis DAPTO 512 during 18 days prior to ß-Lg allergy induction exerts a protecting effect on the murine intestine and induces a significant decrease in the ß-Lg allergenicity.

Polyanion inhibitors of human immunodeficiency virus and other viruses. Part 2. Polymerized anionic surfactants derived from amino acids and dipeptides.

A series of new polyanions was synthesized via gamma-polymerization, in aqueous micellar solution, of omega-unsaturated anionic surfactants whose polar head was derived from amino acids or dipeptides. The obtained polyanions were evaluated for their activity against human immunodeficiency virus (HIV-1, HIV-2) and various other RNA and DNA viruses. All the test compounds proved active against HIV-1 and HIV-2, their 50% inhibitory concentration (IC50) being in the range of 0.04-7.5 micrograms/mL, while they were not toxic to the host cells (CEM-4 or MT-4) at concentrations up to 100 micrograms/mL or higher. The HIV-inhibitory effect increased with the hydrophilic character of the amino acid moiety. The compounds were found to interact with both the viral envelope glycoprotein gp120 and the cellular CD4 receptor, thus blocking virus-cell binding and virus-induced syncytium formation. These polyanions also proved active against human cytomegalovirus at about the same IC50 as for HIV. In addition, they were also active, albeit at somewhat higher IC50 values (0.8-20 micrograms/mL), against other enveloped viruses such as respiratory syncytial virus and arenaviruses (Junin and Tacaribe). At yet higher IC50 values ( > or = 20 micrograms/mL), some of the compounds showed activity against influenza A virus. No activity was observed with any of the compounds against vesicular stomatitis virus, Sindbis virus, Semliki forest virus, influenza B, parainfluenza type 3, and the nonenveloped viruses Coxsackie type B4, polio type 1, and reovirus type 1.